It's implied in a school room at the end of a dark hallway with one way in, covered in motivational posters. The character mentions something along the lines of "This is where the loud kids are taken"
The main character does not have an animation for using the needles on herself, simply dragging the needle (to refill health in this case) to the hud, but there are important points in various chapters that do require you to use needle-like machines.
A character in the game asks the main character to kill them and the main character is required to in order to progress. In addition, text from other characters in the area state that this is not the first time the character has tried such a thing.
The entirety of the game is centred around the main character being lied to by everyone they knew because of what they see when they put on their helmet, as well as the loading screens having a lot of conspiracy theory related and unreality related "real world tips", among other things.
The game's loading screens include "Real World Tips," and if ti counts, the end of the game includes the character literally breaking the screen and causing a switch to a different character.